title: Localization of SMAP2 to the TGN and its function in the regulation of TGN protein transport.
abstract: SMAP2 is an Arf GTPase-activating protein that is located and functions on early endosome membranes. In the present study, the trans-Golgi network (TGN) was verified as an additional site of SMAP2 localization based on its co-localization with various TGN-marker proteins. Mutation of specific stretches of basic amino acid residues abolished the TGN-localization of SMAP2. Over-expression of wild-type SMAP2, but not of the mutated SMAP2, inhibited the transport of vesicular stomatitis virus-G protein from the TGN to the plasma membrane. In contrast, this transport was enhanced in SMAP2 (-/-) cells characterized by increased levels of the activated form of Arf. SMAP2 therefore belongs to an ArfGAP subtype that resides on the TGN and functions as a negative regulator of vesicle budding from the organelle.
authors.affiliation: Institute of Development, Aging and Cancer, Graduate School of Life Sciences, Tohoku University, Sendai, Japan.
authors.forename: Tomo
authors.initials: T
authors.lastname: Funaki
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Kon
authors.forename: Roger E
authors.initials: RE
authors.lastname: Ronn
authors.forename: Yuji
authors.initials: Y
authors.lastname: Henmi
authors.forename: Yuka
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Toshio
authors.initials: T
authors.lastname: Watanabe
authors.forename: Keiko
authors.initials: K
authors.lastname: Nakayama
authors.forename: Kenji
authors.initials: K
authors.lastname: Tanabe
authors.forename: Masanobu
authors.initials: M
authors.lastname: Satake
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002462:Cell Membrane / Q000378:metabolism; D002522:Chlorocebus aethiops; D011992:Endosomes / Q000378:metabolism; D015870:Gene Expression; D006367:HeLa Cells; D006801:Humans; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D021381:Protein Transport; D014759:Viral Envelope Proteins / Q000378:metabolism; D021601:trans-Golgi Network / Q000378:metabolism*
chemical_list: C028391:G protein, vesicular stomatitis virus; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; C529588:SMAP2 protein, mouse; D014759:Viral Envelope Proteins